With the 2015 WRX STI, Subaru opted for evolution instead of revolution. This is after all, a car that many professional and amateur racers rely on to bring them wins on the weekend. With that in mind, the new 2015 WRX STI furthers the platform by improving what needed to be improved, while at the same time retaining components that have brought the car success on road circuits and rally stages around the world.
The most notable carryover is the drivetrain. Specs are identical to the 2013’s EJ257, which leads us to believe it is the exact same engine and turbo setup: bore (99.5mm), stroke (79mm), compression (8.2:1), max boost (14.7 PSI), peak horsepower (305 at 6,000 rpm) and peak torque (290 lb.-ft at 4,000 rpm) are all identical to the outgoing model. Even the 6 gear ratios are identical – with the exception of reverse, which is now 3.545 versus the previous 3.333. Subaru says that the transmission now has triple-cone synchs on 1st and 2nd and a double-cone on 3rd to ease shifting effort and reduce noise and vibration. Sorry kids, an automatic transmission will not be an option.
As before the STI retains the Driver Controlled Center Differential (DCCD), which uses planetary-type center differential gears with a nominal 41:59 torque split. A mechanical limited-slip center differential augments an electronically controlled center differential to shift torque around. Up front is a helical-type limited slip differential, in back a Torsen torque-sensing limited slip differential. Still cool, but nothing new here.
The chassis is where the car starts to look like an entirely different beast. First off, it makes use of much more high-tensile steel than before. It also has numerous stiffening elements to improve handling. The wheelbase has been increased by exactly one inch (up to 104.3-inches) and overall length is up a whopping 7 inches (to 180.9), this should help with stability at high speeds. Width and track are holdovers, but ground clearance has dropped from 6.1-inches to a scant 4.9-inches with firmer shocks from the factory. This lower stance should help the road-handling abilities of the car straight form the dealership, though it may be problematic for STI owners that also use their cars as SUVs on the weekend. Want to go serious rallying? You’ll need new suspension anyhow.
So the new STI is bigger and has the same engine. Not what you hoped for? Don’t worry, there’s a lot more to this new car. If you’ve driven a BRZ and an STI back-to-back one of the most noticeable differences from the driver’s seat is just how slow the old STI’s steering rack is (15:1) compared to the little BRZ’s lightening-quick 13.12:1 setup. The new STI? Even quicker at 13.0:1 with 2.5-turns, lock-to-lock.
Subaru also brings its new Active Torque Vectoring to the STI. Similar to the system introduced in the new WRX, ATV can apply brake pressure (in certain circumstances) to the inside front wheel to provide more neutral cornering characteristics. This works in conjunction with the multi-mode Vehicle Dynamics Control system to provide more driver control on the limit. As before, VDC can be completely disabled for expert drivers.
If you plan to make the new STI your daily driver you’ll likely appreciate improvements made throughout the cabin. Here, Subaru has made great effort to provide a more premium experience. Materials have been upgraded throughout, and the main gauge cluster now includes a standard 3.5-inch LCD, which displays various functions and settings. A second 4.3-inch LCD above the center console is also standard. This larger screen is put to use for the standard rear-view camera, boost gauge, bluetooth, climate systems and VDC activity. Low beam LED headlights, dual-zone climate controls and the all-weather package are also standard equipment.
Beyond the standard model, the new STI will also be available in three special trims including a new “Launch Edition,” which will be limited to a production run of only 1,000 units. The Launch Edition includes 18-inch gold BBS wheels, World Rally Blue paint, Alcantara interior, keyless start and a special STI short-throw shifter.
The STI Limited upgrades the base model with an 8-way power seat, 18-inch BBS wheels, leather interior and an Harman/Kardon premium audio system. Keyless access and start is an option for both Premium and Limited models.
Pricing has not yet been announced.
On paper, this new STI may not sound dramatically different, but neither did the new WRX — and it gobsmacked us with its new abilities. We’re schedule to get some seat time in the new WRX STI mid-February, so look for a review around that time. Have something you want us to look at in particular? Post your comment below. We read them all.